ERF1 -- Enhanced River Reach File 1.2

ERF1 was designed to be a digital data base of river reaches capable of
supporting regional and national water-quality and river-flow modeling and
transport investigations in the water-resources community.

ERF1 has been recently used at the U.S. Geological Survey to support
interpretations of stream water-quality monitoring network data (see Alexander
and others, 1996; Smith and others, 1995). In these analyses, the reach network
has been used to determine flow pathways between the sources of point and
nonpoint pollutants (e.g., fertilizer use, municipal wastewater discharges) and
downstream water-quality monitoring locations in support of predictive
water-quality models of stream nutrient transport.

The digital data set ERF1 includes enhancements to the U.S. Environmental
Protection Agency's River Reach File 1 (RF1)to ensure the hydrologic integrity
of the digital reach traces and to quantify the time of travel of river reaches
and reservoirs [see U.S.EPA (1996) for a description of the original RF1].

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